The Globe and Mail reports in its Thursday edition that U.S. equities have lost more than $4-trillion (U.S.) in value after U.S. President Donald Trump declined to rule out recession as a result of its tariff policies. Guest columnist Kevin Yin writes what the question remains, how did markets not see this coming earlier? Last October, Mr. Trump said that "tariff" is the most "beautiful word in the dictionary." He promised 25-per-cent tariffs on Canada and Mexico as early as November. In January, he reiterated this intention. Four days later, it became clear that the President was entirely serious about implementing tariffs. Wall Street understands that import taxes raise production costs through the price of intermediates, which hurts profits and thus both equity values and gross domestic output. It is as if a blackjack dealer told us the next card was high and we hit anyway. Clearly markets did not expect Mr. Trump to actually implement the tariffs, while they did expect the tax cuts. Investors were swayed by arguments that tariffs were simply a tool for bargaining, as outlined by Bank of America on Feb. 10, and that the negative growth effects of actually implementing them made them unlikely. Well, they came anyway.